The present invention relates generally to a manner by which to transduce communication signals at a mobile, or other communication, station operable in a cellular, or other radio, communication system. More particularly, the present invention relates to an assembly, and an associated method, at which signals generated pursuant to the effectuation of a communication service at the mobile service are transduced and also at which position-indicating signals, such as those generated during operation of a global positioning system (GPS) are transduced. Signals generated at the mobile station and transduced at the antenna transducer do not prevent detection at the antenna transducer of lower-power position indicating signals.
The development, and implementation, of various types of mobile communication systems have been made possible as a result of advancements in communication technologies. A cellular communication system is an exemplary mobile communication system whose development, and implementation, has been made possible as a result of such communication-technology advancements.
In a cellular communication system, telephonic communication, of both voice and data, is generally possible. Other mobile communication systems analogously also provide for the communication of both voice and data. The use of a mobile communication system through which to communicate is advantageous as communications are effectuable by a user from almost any location with which a radio link between communication stations operable in the communication system can be formed. Improved mobility of communications is possible as communication links are formed upon radio links rather than through wire line connections.
A radio transceiver, sometimes referred to as a mobile station, is utilized by a user to communicate telephonically therethrough. The effectuation of the telephonic communications by way of a mobile station operable in the cellular communication system usually appear to the user generally to be similar to operation of conventional telephonic devices.
One aspect of a conventional telephonic device, however, is not easily replicated. The mobile nature of a mobile station operable in a cellular, or other mobile, communication system prevents simple tracking of the location at which a call is placed therethrough. The location at which a call is placed is important, for instance, when a call is placed to request emergency assistance by the user of the mobile station.
When an analogous call is originated at a conventional wire line device, the geographical position from which the call is originated is easily determinable. A simple mapping between the telephonic identity of the originating, wire line device and the location at which the device is installed, indicates the geographical positioning of the originating party. In contrast, because of the inherent mobility permitted of a mobile station, a user of a mobile station is able to originate a call from almost any location within a geographical area encompassed by the cellular, or other mobile, communication system. When the call is placed by way of a mobile station, therefore, the geographical position at which the call is originated is not readily determinable.
Emergency assistance personnel must be able to respond to a request for emergency assistance requested by a user of a mobile station. Otherwise, if the user of the mobile station is unable to identify to the emergency assistance personnel the location at which the call requesting the assistance is made, the emergency assistance personnel might be unable to provide the assistance.
GPS (global positioning system) technologies are implemented to provide geographical positioning information. GPS receivers are available to receive and to detect time-of-arrival signals generated by satellite-based transmitters. Signals received from three separate satellites at a GPS receiver are used by the GPS receiver to determine an accurate, three-dimensional geographical positioning indicia of the GPS receiver when the GPS receiver is synchronized to the satellite.
Incorporation of a GPS receiver into a mobile station used for voice and data communications permits the geographical positioning of the mobile station to be determinable. Such incorporation permits the geographical positioning of a mobile station to be determined through operation of the GPS receiver portion thereof, and appropriate circuitry provides such information to emergency assistance personnel when a call to an emergency assistance center is placed.
When the mobile station is operable in a cellular communication system, voice and data signals transduced by the mobile station are of relatively high power levels, e.g., power levels of one-half watt, or higher. Although the GPS signals and the cellular voice and data signals are generated within separate frequency bands, the relatively high energy levels of the cellular-system-generated signals, particularly the signals originated at the mobile station, include harmonic, and other, components that might interfere with detection at the mobile station of the GPS signals transmitted thereto.
Conventionally, therefore, when constructing the mobile station, the GPS antenna transducer is positioned as far away as possible from the antenna transducer used by the radio transceiver circuitry of the mobile station. The existing need to separate the antenna transducers is contrary to the competing design goal to miniaturize the mobile station. And, the conventional need to utilize separate antenna transducers increases the part-count of the mobile station, increasing, thereby, the construction complexity and expense associated with construction of the mobile station.
If a single antenna transducer assembly could be provided capable of use by both the radio transceiver circuitry and also the GPS, or other positional-indicia, circuitry of the mobile station, miniaturization and reduced-cost goals would be facilitated.
It is in light of this background information related to antenna transducers utilized in radio communications that the significant improvements of the present invention have evolved.
The present invention, accordingly, advantageously provides an assembly, and an associated method, by which to transduce communication signals at a mobile, or other communication, station operable in a radio communication system, such as a cellular communication system.
Through operation of an embodiment of the present invention, a manner is provided by which to transduce, at a single antenna transducer construction, both signals generated during normal operation of a cellular, or other mobile, communication system as well as position-indicating signals.
An antenna transducer constructed pursuant to an embodiment of the present invention is of compact dimensions, readily positioned within the housing of a mobile station. The antenna transducer is capable both of detecting the position-indicating signals and also transducing communication signals normally generated during operation of the cellular, or other mobile, communication system in which the mobile station, of which the antenna transducer forms a portion, is operable.
An antenna transducer constructed pursuant to an embodiment of the present invention integrates a primary cellular mobile telephone (CMT) antenna transducer part and a GPS (global positioning system) antenna transducer part. Because of the integration of the antenna transducer parts into a single assembly, reduced size requirements, reduced parts-counts, and corresponding reduced assembly-step requirements are provided. Increased miniaturization of packages in which a mobile station incorporating the antenna transducer of an embodiment of the present invention as well as reduced assembly costs are possible through use of an embodiment of the present invention.
A manner is provided by which to position the antenna transducer parts in a way that isolation between the two antenna transducers at a GPS frequency band is exceptionally good, for example, greater than 30 dBs, if optimally designed. And, the radiation properties, e.g., the polarization and radiation patterns of the antenna transducer part utilized for cellular, or other mobile, communications are suitable for GPS reception.
In one aspect of the present invention, a primary antenna transducer portion is formed of transmission lines disposed upon a substrate. The primary antenna transducer portion operates to transduce both forward-link signals and reverse-link signals generated during normal operation of a cellular, or other mobile, communication system. The transmission lines are implemented, for instance, as conductive paths formed of two arm members formed upon the substrate. Through appropriate selection of the lengths of the arm members of the primary antenna transducer portion, energy transduced thereat cancel each other at a selected operational frequency.
In a further aspect of the present invention, a second antenna transducer portion is also formed of a transmission line, disposed upon the same substrate upon which the primary antenna transducer portion is disposed. The second antenna transducer portion is positioned relative to the primary antenna transducer portion at a selected separation distance such that energy transduced by the primary antenna transducer portion induces, or facilitates, the second antenna transducer portion to exhibit circular polarization characteristics.
In one implementation, an antenna transducer construction is provided for a mobile station operable in a cellular, or other mobile, communication system which also includes a GPS (global positioning system) receiver. The GPS receiver is operable to receive GPS signals transmitted thereto at frequencies about a 1575.42 MHz frequency. The primary antenna transducer portion and the second antenna transducer portion are formed of transmission lines disposed upon a substrate. The portions are separated from one another in manners such that operation of the primary antenna transducer portion facilitates circular polarization characteristics to be exhibited by the second antenna transducer portion. A notch in the coupling between the antenna transducer portions is provided such that at the operational frequency of the GPS receiver, i.e., here, approximately 1575.42 MHz, energy of the primary antenna transducer portion is of reduced levels.
In these and other aspects, therefore, apparatus, and an associated method, is provided for a radio device. The radio device operates upon first radio signals communicated within a first frequency bandwidth and second radio signals communicated within a second frequency bandwidth. An antenna transducer is formed upon a substrate. A primary antenna transducer portion is disposed at the substrate. The primary antenna transducer portion transduces the first radio signals. The primary antenna transducer portion has a first primary antenna transducer part and a second primary antenna transducer part. A second antenna transducer portion is also disposed at the substrate. The second antenna transducer portion transduces the second radio signals. The second antenna transducer portion is positioned relative to the first and second primary antenna transducer parts such that energy transduced by the first and second primary antenna transducer parts cancel one another within the second frequency bandwidth.
A more complete appreciation of the present invention and the scope thereof can be obtained from the accompanying drawings which are briefly summarized below, the following detailed description of the presently-preferred embodiments of the invention, and the appended claims.